New simulation of Phobos Stickney crater

In this work we model the Phobos Stickney impact crater using the iSALE hydrocode and considering different scenarios that could form the well-studied crater

Phobos spectral clustering: first results using the MRO-CRISM 0.4-2.5 micron dataset

Whether Phobos is a captured asteroid or it formed in situ around Mars, is still an outstanding question within the scientific community. The proposed Japanese Mars Moon eXploration (MMX) sample return mission has the chief scientific objective to solve this conundrum, reaching Phobos in early 2020s and returning Phobos samples to Earth few years later. Nonetheless, well before surface samples are returned to Earth, there are important spectral datasets that can be mined in order to constrain Phobos' surface properties and address implications regarding Phobos' origin. One of these is the MRO-CRISM multispectral observations of Phobos. The MRO-CRISM visible and infrared observations (0.4-2.5 micron) are here corrected for incidence and emission angles of the observation. Unlike previous studies of the MRO-CRISM data that selected specific regions for analyses, we apply a statistical technique that identifies different clusters based on a K-means partitioning algorithm. Selecting specific wavelength ranges of Phobos' reflectance spectra permits identification of possible mineralogical compounds and the spatial distribution of these on the surface of Phobos. This work paves the way to a deeper analysis of the available dataset regarding Phobos, potentially identifying regions of interest on the surface of Phobos that may warrant more detailed investigation by the MXX mission as potential sampling areas. Acknowledgments: M. Pajola was supported for this research by an appointment to the NASA Postdoctoral Program at the Ames Research Center administered by USRA

Recent collisional history of (65803) Didymos

The Double Asteroid Redirection Test (DART, NASA) spacecraft revealed that the primary of the (65803) Didymos near-Earth asteroid (NEA) binary system is not exactly the expected spinning top shape observed for other km-size asteroids. Ground based radar observations predicted that such shape was compatible with the uncertainty along the direction of the asteroid spin axis. Indeed, Didymos shows crater and landslide features, and evidence for boulder motion at low equatorial latitudes. Altogether, the primary seems to have undergone sudden structural failure in its recent history, which may even result in the formation of the secondary. The high eccentricity of Didymos sets its aphelion distance inside the inner main belt, where it spends more than 1/3 of its orbital period and it may undergo many more collisions than in the NEA region. In this work, we investigate the collisional environment of this asteroid and estimate the probability of collision with multi-size potential impactors. We analyze the possibility that such impacts produced the surface features observed on Didymos by comparing collisional intervals with estimated times for surface destabilization by the Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect. We find that collisional effects dominate over potential local or global deformation due to YORP spin up.Project (PGC 2021) PID2021-125883NB-C21, by MICINN (Spanish Government): A.C.B., L.M.P., P.G.B. Call 2023 of the Italian National Institute for Astrophysics (INAF, act n. 38/2023): A.D.O. ESA funding through the Science Faculty—Funding reference ESA-SCI-SC-LE-191: P.G.B. “Margarita Salas” postdoctoral grant by the Spanish Ministry of University—NextGenerationEU: L.M.P. CIAPOS/2022/066 postdoctoral grant (European Social Fund. Generalitat Valenciana): L.M.P. Italian Space Agency (ASI) funding within the LICIACube project (ASI-INAF agreement n. 2019-31-HH.0): A.L., M.P. HERA project (ASI-INAF agreement n. 2022-8-HH.0): A.L., M.P

Spectral Clustering and Geomorphological Analysis on Mercury Hollows

Characterization of hollows located in different craters to understand whether there is a similar trend from a compositional point of view, and whether a possible correlation exists between spectral behavior of hollows and geomorphological units

Multidisciplinary Analysis of Lermontov Crater on Mercury

We present the geological, age determination, and spectrophotometric analysis of the Lermontov Crater on Mercury

Main Belt Comets as Clues to the Distribution of Water in the Early Solar System

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Asteroids Inside Out: Radar Tomography

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